That's right PDM.
It is true, when you look at someone that you are highly attracted to, whether physically or emotionally your pupils automatically dilate to let in more light so you can see that person better.... Its neat what you learn in college psychology classes lol
But on to your query. When I show interest in a girl I try and be real polite to them, treat them differently than anyone else as in just paying attention to them more and trying to hang out with them more. Glancing into her eyes more often and just trying to make her feel comfortable. But this is just me, back in High school I was different and idk what this guy's attitude or anything is like so I can't be too concise on how he might show his interest but u get the basic idea
